Excavating-machine.



M. G. BUNNELL.

EXGAYATING MACHINE. APPLIOATION FILED 121113.23, 1910.

- Patnteol Mar. 9, 1915.

WTA/555.55

d r v 4 lll) those for making ditches,

v' thekind known as trenchers. ln the use of machinery of this kind` it frequently happens that great difculty 1s experienced 1n making thefbottom'of the ditch or trench' `follow' a certain 'anemia u i. t d

lto.

nicht o. 'nummern enmarcado, ILLINOIS, nssrcnon ro rnnnnnicn: c. AUSTIN,

. n or omesso, rumors.

insenature-MACHINE.

'a citizen of the United 4States of merica,

' and' resident: of Chicago,

Cook county, Illinois, have invented a certain new and useful improvement in Excavat1ng--Ma- -c:1ines,of which the following is a specification. l' 4.

My' invention relates' to excavating machines in general, -butmore particularly to and especially to 'predetermined grade line,

owing to inequalities in thesurface of the ground.- .'Vjery often the grade line 'or di#v- I J rection of the ditch, when viewed from the' such-case the machine must be4 4adjusted 1 oiten'inorder to keep 'the excavation from i oing above orvbelow the grade'l1ne-.j;.= lff4 ie machine starts down hill, then the exside, does not follow the surface line,.an`d in cavating apparatus at the rear must' be adjusted to. prevent the bottomof the trenchA grade line; andif the-i from rising above the m'achinefstarts` up hill,v "then tlie apparatus must he given the opposite adjustment 1n order to prevent it from going below the grad@ line.

over, the necessity asses on to either scribed for the bottom of the trench, and

' whereby the adjustment curate than heretofore.

ln the Aaccompanying' drawings-Figure l embodying as thus uiustraaa, asoman is of that' well blown type in which a body A l f Specification of Letters Patent.-

' or suitable means however, I now which is stretched-on lstakes e above `the 'Prior 'to my invention it wasggf-ground, and which is a matterv 'of some diliculty to determine:-KA these adjustments accurately, and, morefor adjustment `was not always instantly 'and readily-apparent.

The object .of my invention is, therefore,1 to provide an arrangement whereby 4the necessity `for adjustment to maintainv a certainf grade line will at 'once' become' manlfest,

*struck from the of the curved bar F is kept in the or for any other"A` for such purpose,y when required, will be more easily made ac-fl the said -bar Patented Mar.. 9, agio..

@application mea rebruary es, 1ero.4 serial No. 546,347.

mounted on front wheels B and on rear `tractors C. The trenching apparatus, for making a trench or ditch, comprises the adjustable frame D upon which is mounted the traveling chain belt d having the excavating buckets d. For' convenience of illustration, only Aone 'or two buckets are shown, but-it will be understood that any number wmay be employed on said belt, as well as cutters or otherknown devices for forming a trench 'in the ground. The said excavating apparatus is at the rear of the excavator, and hence a narrow trench is formed :1s-the machine slowly moves. forward. l rllhis is 'all well known. The usual are employed for raisins' and lowering the frame D to vary the depth termined depth. -If the forward topreserve the grade line for the bottom of theditoh. On the other hand, if the machine starts uphill, then the frame D must be-'raised-to prevent ,the excavation from 'extending below\ the grade line. Heretofore theoperator has accomplished this as best he could. ln accordancewith my invention, providea line or-wire E parallel with the grade bottomof the ditch. I'provide acurved bar F on the line of a circle vcenter or axis of the sprocket wheelsal2 at the bottom of the said frame.A The link belts d having the lexcavating ybuckets and other devices travel around these sprockets. If the periphery same horizontal plane as the wire E then Vthe grade line will be preserved and the 'bottom of the 'ditch-'will be everywhere the samedistan'ce below'the said wire. Suppose, for example, that the forward end ofthe line -desired for the n the frame D which, i's-formed tor can then restoret'the excavating ap aratus tothe right level by lowering the iii-ame ID until the bar F wire E. 0r, if the machine starts ,up hin, then the operator raises the vframe' D until F is brought into line with said wire. Thus, and regardless of the vangl-e of the frame D, the *grade line will be premachine sud- -denly dropsdown. -lln such case the opera-4 is again' in line with theV served so long as the periphery of the bar F 'is maintained on a level with the wire E.

If desired, the bar F can be disposed immediately below the said wire E, as shown in Fig. 2. With this arrangement, and in order to keep the machine working at the proper grade line, it is only necessary for the operator to keep the bar F just barely in touch with the said wire. This makes it very easy vfor the operator to preserve any given or predetermined grade line.

Another way of using my invention is as followszThe bar may be used by the opera Vtor to preserve the grade line by sighting, relative to a series of objects, such as a line of posts, if such is desired. Here, also, the operative point on the indicator is always above the axis about which the bar is curved. The bar f is, therefore, in the nature of an indicator arm for determining the adjust'ment necessary for preserving a certain grade line. Being curved, as shown, the indicator is. operative at any angle of the frame D, as the point of contact of the indicator with the wire is always directly .above thelower axis of the excavator-that i is, above the axisl of the wheels d2 of the excavator. g l It will be understood that my invention serves equally well to keep the ditch in a straight line, when viewedfrom abovethat is to say, should the machine swerve to the right or theleft, such deviation will 4o for. the* boafaef the dach, and this wir@ y can' bestraight 'or madev to follow a curve,

"eithergto the-right or to the left, or can he r' lgiven-any other Vdesired direction. So long as thief-.operator makes the machine follow f thewire, the grade line vof the ditch and the direction 'thereof will be in accordance with previous' calculations. With my invention ,thegnecessit'y for adjustment is not only i veas'ily .jdiscernib1e, but isalso more easily Wx-made? accurate after such necessity becomes anifest. AIhe highest point on the curved f'cator. bar must be maintained in line .j ithrdolr close to the wire, and this will prel`serye'fthe grade line, regardless of the angle ,5 5 at which the bucket frame is operating.

'.Thelline above ground, relative to which the .curved indicator bar is maintained in close relation to maintain the grade, may be ...a wir@ or rope, or itmaybe an imaginary y sighting from one ob- With .the construction .showndescribed, the indicatin point on the bar F is always on a vertica line which intersects f @gt-the axis of the sprockets d2, for regardless ber curved about a center at the lower end of said element, movable therewith and in.

.velement, whereby said element, when disof the angle of the frame D, the point on the bar F which must be kept in line with the wire is always the highest point *thereon. If the frame D is tilted in one direction, this moves the indicating point toward one end of said bar F-that is to say, the point to be kept on the wire will then be found to have shifted toward one end of the bar; but if the frame D is tilted in the other direction, then the operative point on the bar F will be shifted in the other direction.

But always, as stated, this indicating point is on a vertical line which intersects the axis of the wheels d2, and the curvature of said bar F constitutes the means for causing this.

What I claim as my invention is:

l. In an excavator, an element whicli works in the ground to form the ditch, and an indicator on said element, movable therewith, in fixed relation thereto, adapted to g5. coperate with a line above ground, comprising a member having'an edge curved 'f about a point at the lower end of said ele- 'l ment, whereby the grade line is maintained for the ditch.

2. In an excavator, an element which works in the ground to form the ditch, having an axis of operation for the lower end thereof, means whereby the said element is subject to variations in the angle thereof, means above the ground for determining the grade line of the bottom of said ditch, and mechanism for indicating any up and down deviation from said line, said mechanism havingmeans for keeping the indicating point thereof (for all operating angles of said element) on a vertical line intersecting said axis.

3. In an excavator, an element which which works in the ground to form the ditch, pivoted at its upper' end, adapted to beraised and lowered on the excavator to vary or preserve the grade line, and an indicator on said element for showing' deviation from the grade line, including a meml fixed relation thereto, projecting rearwardly x therefrom, disposed above ground, adapted to indicate the necessity for and character of adjustment required to maintain the .grade line.

4. In an excavator, an element which works in the ground to form the ditch adjustable to different angles, a grade line suitably supported above ground, and a curved indicator on said element, projecting rearwardly therefrom, disposed above ground, said indicator being formed on the line of a circle struck from a point at the lower end of said posed at different angles, but always with the `periphery of said indicator on said grade line, will keep the bottom of the ditch a uniform distance below said line.' 13@ mamie 5. lin an excavator, an. element which Works in the ground to form the ditch, adapted to be disposed at different angles, by tilting in a vertical plane, and a curved indicating arm thereon, said arm being formed on the line of a circle struck from an axis at the lower endr of said element, said element having supporting means arranged for rotation about said axis.

6. ln an excavator, a grade line indicator therefor, having means for keeping the inthe line of a circle 

